Heretofore it has been known, in the prior art, that water, when added to the combustible mixture or motive fluid supplied to the engine, could provide a cooling effect upon such mixture or motive fluid and could, in effect, increase the effective octane number thereof thereby, of course, improving the anti-knock quality of the combustible mixture and the smoothness of engine operation.
However, the problems associated with the proper delivery of such water have, in the prior art, prevented a general acceptance of such water injection. In order to obtain the benefits of water injection, the rate of flow of the water being injected should have some relationship at least to the engine load and speed. Heretofore, the prior art has employed a vacuum actuated switch which, when actuated at a preselected magnitude of engine or intake manifold vacuum, would permit the continued flow of water to be supplied to the engine for all subsequent conditions of engine operation which produced an engine or intake manifold vacuum equal to or less than the said preselected magnitude.
The prior art has also proposed providing a reservoir of water with a conduit connection to the fuel induction passage means wherein such water would be discharged into the induction passage means by aspiration. Also, other very complicated and costly metering systems have been proposed by the prior art; however, as already stated, none of such prior art systems have enjoyed general acceptance.
Accordingly, the invention as herein disclosed is primarily directed to the solution of at least some of the problems of the prior art structures and to the providing of a water injection system which is relatively inexpensive, dependable in operation and effective for providing water injection at a rate which effective for producing the desired effect for those conditions of engine operation wherein the said effect is most beneficial.